Abrasive disk



Jan. 13, 195,3 v.v| LooFBoRo ETAL 2,624,985

ABRAsIvE DISK Filed'July 19, 195o 2 SHEETS-SHEET 1 EEZ . Erzi INVENTORSVernon L. Loo'bora Robert @White @nl ZAM-J Al-s.

Jan. 13, 1953 v. L. LooFBoRo r-:rAL 2,624,986

ABRAsIvE msx Filed July 19, 195o 2 SHEETS- SHEET 2 INVENTORS e non L.Looftgor-o bert C1, M/hd'e BY/Za I Patented Jan. 13, 195,3

ABRASIVE DISK Vernon L. Loofboro, Rockton, Ill., and Robert A. y White,Beloit, Wis., assignors to Gardner Machine Company, South Beloit, ill.,a corpora*- tion of Illinois Application July 19, 1950, Serial No;174,722

11 Claims. 1,-

The present invention .pertains generally to grinding Wheels and morespecifically to an improved reinforced abrasivedisk of the general typedisclosed in United States Patents 1,964,537, 1,964,538, and 1,964,539,all 'issued June 26, 1934, to Ingle R. Shue. The-subject matter of thepresent application is closely related' to that contained in ourcopending. applications, Serial Nos. 174,723'and 174,724 led intheUnited States Patent Oice on July 19, 1950.

Abrasive disks of the type-under consideration here usually have arelatively small thickness in comparison to their diameter. To adaptthem to high speed grinding operations, it is a common practice toreinforce such disks internally and mount them upon an appropriaterotary support or backing surface. Upon vmore particular reference tothe foregoing patents. it will be noted that each of the disksthereshown is rein-forcedinternally as by means of a wire mesh or gridbarely covered by the-abrasive material defining its rear or mountingface. The disk is secured against the supporting Wheel by screws whichengagenuts disposed in engagement with theV face of the mesh remote fromthe mounting face of the disk.

While abrasive disks constructed in the above manner lhave beencommercially satisfactory, they have :also been subject to a number ofdisadvantages. 'Ihus the vlocation of the reinforcing mesh in close'proximitywith the rear face of the disk detracts-from theA strength ofthe same and sometimes resultsy in-cracking-away Iof the abrasive fromthose points on the mesh nearesty the rear face of the disk. Suchcracking away is particularly noticeable in theregions of the attachingnuts since the clamping pressure exerted by the latterl sets up acrushing action upon the underlyingv abrasive. Moreover, in disks whichoperate at high. rotational speeds, it is desirable to^locate theinternal reinforcement as close as possible to: the itransverse'medialplane of the disk so as to set upa maximum resistance to `centrifugalforce. ItJisf-With the elimination of the foregoing disadvantages thatthe present invention is concerned.

One object lof the invention is to pr-ovide an abrasive disk of the`character-set forth and which will have greater Vstrength and a'highersafety factor than any such disks-heretofore produced.

Another object isto provide an` abrasive disk of the above typehavingfarlimproved mounting means together with a novelcorrelationbetween such means.A and the finternal reinforcing mesh of thedisk,..such correlation:-,contributing :sube

stantially to the increased strength of the disk. A further o'bject isto provide an abrasive disk of the foregoing type and comprising areinforcing mesh together with Imounting members susceptible of assemblyinto an integral self-contained structure which can be moved aboutbodily during manufacture of the disk.

Still another object is to provide a disk of th foregoing characterand'Which Will be susceptible of economical manufactureon a massproduction basis.

Other objects and advantages will become apparent as the followingdescription proceeds, taken in connection with the accompanyingdrawings,` wherein:

Figure 1 is a face view of the mounting surface of an illustrative diskembodying the present 'invention, a portion of the abrasive materialhaving been cut aW-ayto illustrate more fullythe internal reinforcementof the disk.

Fig. 2 is a side vieW'of the'abrasive disk shown in Fig. 1, `such diskbeing mounted in place lupon a rotatable supporting wheel.

Fig. 3 is an enlargedv fragmentary transverse sectional view throughythe villustrative abrasive disk' and its supporting Wheel, such 'viewbeing taken in the planeof the line 3"-3'in Fig. 1.

Fig. 4 is la plan view of certain parts of the disk illustrated in Fig.y3,V the 'abrasive having' been omitted to permit clearer-illustration ofthev internal members Vof `the disk."

Figs. 5 -and 6 `are enlarged fragmentary views correspondingrespectively to Figs. 3 and 4 but de'- tailing a modified form `ofabrasive disk also ernL bodying the invention.

Figs. 7 and 8 are enlarged Vfragmentary views alsocorrespondingrespectively'to Figs.V 3 an`di4' but detailing stillanother' modification falling within the scope'of the-present invention.

Figs. 9-and lOare enlarged fragmentary sectional views similar to Fig. 3but illustrating two' Referring moreV specifically to" 'the drawing;there' '1s .showniin Figs.` l and i2" an illustrative abrasive disk 26embodying the present invention and susceptible of attachment to arotatable supporting wheel 2|. In the present instance. the disk is offlat annular shape, being formed with a central recess 22 together witha grinding face' 24 and a mounting face 25 which abuts against face 26of the supporting wheel. Substantially coextensive with the disk 20 andimbedded in the body 28 thereof is a metallic reinforcing mesh 29 whichhappens in the present instance to be a wire grid. operativelyassociated with the mesh 29 and partially imbedded in the body 28 of thedisk are a plurality of fastening members 30 by means of which the diskmay be attached to the supporting wheel 2| Means is provided foreffecting a direct mechanical connection between the abrasive disk 20and the supporting wheel 2| without danger of subjecting the abrasivematerial to crushing or shear stresses normal to the plane of the disk.

This is accomplished by forming the fastening members 30 asnon-deflectable compression members each terminating in a laterallyenlarged stationary bearing surface 3| coplanar with the mounting faceof the disk. Since the fastening members are identical with each other,a description of one will suffice for all. Referring in particular toFigs. 3 and 4, it will be perceived that the fastening member 30 thereshown has an intermediate section of reduced diameter and is adapted forinsertion through a corresponding one of the interstices of the mesh 29.In addition, the member 30 has a pair of lateral enlargements spacedapart by such intermediate section and which snugly sandwich theunderlying marginal portion of the mesh therebetween. By reason of thisarrangement the member 30 is rigidly secured to the mesh 29 with itsbearing surfaces 3| coplanar with the mounting face 25 of the disk anddisposed in axially spaced relation to the plane of the mesh 29.

In the present instance, the member 30 comprises a nut 32 adapted tothreadedly receive the end portion of cap screw 34 projecting axially ofthe supporting wheel 2|. The screw 34 runs from a, counterb'ore 35 inthe rear face of the supporting wheel 2| and extends through the frontface 26 of the wheel 2| as well as through the mounting face 25 of theabrasive disk 20. The intermediate section of the member 3D is definedby a shank 33 of appropriate size to fit through one of the intersticesof the reinforcing mesh 29. The end of the shank 33 projecting towardthe grinding face 24 of the disk is adapted for snug engagement with alateral enlargement such as snap-on spring washer 36. The latter is ofsuitable diameter to overlie and abuttingly engage a marginal portion ofthe mesh 29 surrounding the shank 33. To facilitate engagement with thewasher 36 and to better preclude disengagement of the same, the shank 33may optionally be provided with a shallow peripheral groove 38. The endof the shank 33 adjacent the mounting face 25 of the disk terminates ina second lateral enlargement in the form of an integral head 39preferably of hexagonal or some other non-circular geometrical shape.The laterally enlarged head 39 underlies and abuttingly engages amarginal portion of the reinforcing mesh surrounding the shank 33, suchportion of the mesh being tightly sandwiched between the head 39 and thewasher 36. As clearly indicated in the drawing, the head 39 terminatesin the large and substantially annular stationary 4 bearing surface 3|coplanar with mounting face 25 of the disk.

By reason of the construction just described, it will be noted thataxial play of the fastening member 30 relative to the reinforcing mesh29 or to the disk body 28 is completely eliminated. Consequently, whenthe cap screw 34 is tightened to secure the disk 29 in abutment with thesupporting wheel 2|, the resulting clamping pressure is transmitted bymetal-to-metal contact over a wide annular area coextensive with thebearing surface 3|. The clamping stress applied to the disk 20 is takenup simply as compression within the nut 32 itself. Due to this fact, andalso the fact that the comparatively large annular bearing area 3|minimizes the unit pressure on the metal-to-metal contacting surfacesbetween the nut 32 and the wheel 2|, the outer face of the nut head 39will not be forced out of coplanar relation with the mounting face ofthe disk by penetration into the face 26 of the supporting wheel.Consequently, there is no danger of subjecting the abrasive material tocrushing or shear stresses in a direction normal to the plane of thedisk 2D. A certain amount of stress in the plane of the disk 20 may betransmitted to the abrasive body 28 but the latter is well able towithstand such stress if present. In any event, stress in this directionis offset somewhat by the frictional contact between the lateralenlargements of the member 30 and the mesh itself, as well as frictionalcontact between the bearing surface 3| and the base' 26 of thesupporting wheel. To avoid undesirable concentrations of stress at theends of the cap screws 34, the body 28 of the disk is preferablyfashioned with a slight clearance recess 40 adjacent the projecting endof the shank 32.

In order to recess the reinforcing mesh 29 well within the body 28 ofthe disk and as close as possible to the medial plane of the same,advantage is taken of the laterally enlarged nut head 39, its thicknessin a, direction normal to. the plane of the disk defining the spacebetween the mounting face 250i the disk and the plane: Thus all portionsof the mesh.

of the mesh 29. 29 are located well within the body 28 of the disk andthe possibility of exposure of the mesh due to chipping or breaking awayof very thin areas of abrasive is effectively precluded.

Turning now to Figs. 5 and 6, there is fragmentarily shown a modifiedembodiment of the invention in the form of a disk 20A having a pluralityof modified fastening members 30A such as the one illustrated in thedrawing. In view of the close similarity between the disk 20A and thedisk 20, like parts will be designated by the reference characters usedearlier herein. In the present instance, the member 30A comprises a nut44 having a threaded shank 45 which projects through an interstice ofthe mesh 29 to engage a lateral enlargement in the form of a coactingnut 46. The nut 46 is adapted to abuttingly engage the underlyingmarginal portion of the mesh 29 surrounding the interstice and tosandwich such portion snugly against a second lateral enlargement in theform of head 39 of the nut 44. The outer face of the head 39 is spacedaxially from the plane of the mesh 29 and defines a laterally enlargedsubstantially annular bearing area 3| ooplanar with the mounting face25. After the nut 46 is tightened securely against the head 39 duringthe manufacture of the disk 20A, the abrasive materialof the body 28 isforced therearound to preclude unscrewing of the.

aczgeee,

nut et and to permanently. nx the head39 with bearing surface 3lcoplanar with thedisk mounting face 25. Thus upontightening of cap screwttl, no crushing or shear stresses are applied to the abrasive in adirection normal to the plane of the disk 29A. Any reaction to thetendency of the member 30A to turn in the plane of the disk as the screw3,4 is tightened can be easily withstood by the abrasive body 28. As inthe case of the fastening member 30, the head 39 of the member 30A is ofsuflicientv thickness to imbed the mesh 29 well within the body 28 ofthe abrasive so as to increase its` resistance tov centrifugal stressesand also to preclude surface cracking.

Figs. 7 and 8 disclose fragmentarily still another disk B having modiedfastening members 39B embodying. the invention. Inthis instance, eachmember B comprises a, nut 4,9 generally similar to the nuts 33, butwhich isY secured to the mesh 29 in a, somewhat different manner.Accordingly, the nut 49 has xed to the projecting end portion o f itsshank a spring washer 59 which engages the underlying face of the mesh29, pressing the same against laterally enlarged head 39 of the nut. Tohold the washer 59 in place, the end ofthe shank is upset as at 5l, suchupset portion engaging land partially overlying radial prongs 52 of thewasher. When secured in place by the means just described, the fasteningmember 30B behaves in a manner substantially identical with that ofthemembers 30, 39A described earlier herein.

Figs. 9 Yand 10 disclose fragmentarily additional modifications of theinvention in the form of illustrative disks 20C, 26D having fasteningmembers 30C, 30D respectively. In the disk 20C, the fastening member 39Ccomprises a nut 55 similar to those described above but having fixed toits upper end a relatively heavy dished washer 56. The latter is sweatedor press it to the shank 58 of the nut 55 so as to clamp the surroundingmargins of the mesh 29 against laterally enlarged head 39 of the nut.Clamping of the disk 29C to the supporting wheel 2| may be eiected as bymeans of the cap screw 34 in the manner described earlier herein.

Modied fastening member 30D of the disk 20D (Fig. 10) (,:omprisesaV nut60. having an upstanding shank 67| terminating in a lateral en.

largement at the end adiacentvthe grinding face 24 of the disk. As thedrawing indicates, the end portion 62 of the nut is integral with thesame and of frusto-conical shape, tapering toward the face 2d. In theconstruction of the disk 26D, the nut 60 may be forced through one ofthe interstices of the mesh 29 due to the taper of the end portion 62,thev mesh springing back into its original shape after the nut ispositioned therein. By proper proportioning of the parts, the nut 6G maybe mounted so that it clampingly engages the surrounding portion of themesh 29 between the flared skirt of thelateral enlargement 62 and thelaterally enlarged head 3 9 oi the nut. The frictional effect betweenthe nut and the mesh 29, together with the. forceset up by the abrasivebody 2 8V in the plane of therdisk, serve to secure the nut 6i) againstturning upon tightening of the cap screw` 34. The outer faceof the head39 denes a laterally enlarged stationary bearing surface. 3i coplanarwith the mounting face 25 of the disk and precludes the setting up ofclamping or crushing stressesv in the abrasive normal to the plane ofthe disk in the manner described earlier herein.

Upon reflection, itv will `be appreciated. that there has been providedak plurality ofdisk con; structions adequately meeting thelobiectivesset forth above. In addi-tion to improving the con.

sheet metal stamplgs which lend themselves,

readily to mass productive operations. Although such fastening members,`are well'adapted to` be fixed to the reinforcing. mesh to. denne endete`gral, self-contained structure capable of being moved bodily asanincidentto manufactured a disk, it might be observed thatY they are.alsostls-- ceptible of beine assembledl in the meldior the. disk.

We claim as our inventienr 1. A, remicreed abrasive disk.A adapted ier'mounting `upon a rotatable, supporting wheel and: comprising, incombinatiom areinforcingmeshp a body of abrasive material molded aboutsaid mesh and having a grinding face` and a mounting face, said meshbeing recessed well withinsaid body between said grinding and saidmount-- ing faces, fastener members imbedded Within said body and eachhaving spaced apart lateralI enlargements sandwichingV said meshtherebetween as well as a reduced intermediate portion passing through`the mesh, said membersA` beingv disposed in radially` andcircumferentially spacedrelation with respect to each other, one ofsaidlateral enlargements of each fastenermember` having an area largerthan the cross-sectional` fastener memberhaving an intermediate portion.

terminating in a pair of axially spaced laterally enlarged portionsclampingly secured in engage-V ment with bothfaces oi'said mesh, saidfastener membervbeingY imbedded in said body with one of said` laterallyenlarged portionsterminating in a relatively large stationary bearingIface "coplanar with the` mounting face of the abrasive disk, saidstationary bearing face being vsubstannelly larger in area thenthe,croserseeteneleree.

of Seid intermediate portion. 0i Seri fastener engagementwith theoppositeface of said mesh.. oneof said lateral .enlargements terminatinginv a relatively large stationary bearingiface axiallylv spaced from theplane of said mesh and coplanar with the mounting face of said disk.said stationary bearing face being larger than the crosssectional areaof said shank.

4. In a reinforced abrasive disk adapted for mounting upon a rotatablesupporting Wheel, the combination comprising a wire reinforcing mesh, abody of abrasive material molded about said mesh and having a mountingface, a fastener nut imbedded within said body and having a rst lateralenlargement of non-circular cross section together with a shank disposedin projecting relation through one of the interstices of said mesh, anda second lateral enlargement fixed to said shank adjacent the end remotefrom said first lateral enlargement and adapted to sandwich a marginalportion of said mesh thereagainst, one of said lateral enlargementshaving an outer face defining a relatively large stationary bearing areacoplanar with the mounting face of said body, said stationary bearingarea being larger than the cross-sectional area of said shank.

5. In a reinforced abrasive disk adapted for mounting upon a rotatablesupporting Wheel, the combination comprising a Wire reinforcing mesh, abody of abrasive material molded about said mesh and having a grindingface and a mounting face, said mest being embedded within said body andspaced apart from said grinding and said mounting faces, a fastener nutimbedded within said body and having a laterally enlarged. head ofnon-circular cross section together with a shank disposed in projectingrelation through one of the interstices of said mesh, said head havingan outer face defining a relatively large stationary bearing areacoplanar with the mounting face of said body and larger than thecross-sectional area of said shank, and a lateral enlargement xed tosaid shank adjacent the end thereof remote from said head, said lateralenlargement being adapted to sandwich the underlying marginal portion ofsaid mesh against said head.

6. A reinforced abrasive disk susceptible of detachable connection to arotatable supporting wheel and comprising, in combination, a reinforcingmesh, a body of abrasive molded about said mesh, said body having agrinding face and a mounting face spaced axially from said grindingface, a plurality of mounting nuts imbedded within said body and eachhaving a shank portion projecting through one of the interstices of saidmesh, a spring washer lockingly mounted on each said shank in clampingrelation with one face of said mesh, a laterally enlarged head integralwith the opposite end of each said shank and disposed in clampingengagement with the opposite face of said mesh, said enlarged headterminating in a metallic bearing face axially spaced from the plane ofsaid mesh and coplanar with the mounting face of said disk, said bearingface being substantially larger in area than the crosssectional area ofsaid shank to present a substantial metallic bearing at the mountingface and prevent transfer of clamping stress to said abrasive body.

7. In a reinforced abrasive disk susceptible of mounting upon arotatable supporting wheel, the combination comprising a wirereinforcing mesh, a body of abrasive material molded about said mesh andhaving a mounting face thereon, a mounting nut imbedded within said bodyand having a shank projecting through one of the interstices of saidmesh, said shank having a perinheral groove adjacent its projecting end,a

spring washer mounted on said shank and disposed in locking engagementwith the peripheral groove, said spring washer being adapted toclampingly engage one face of said mesh, a laterally enlarged head ofpolygonal cross section integral with the opposite end of said shank anddisposed in clamping engagement with the opposite face of said mesh,said enlarged head having an outer face coplanar with the mounting faceof said disk and of substantially larger size than the cross-sectionalarea of said shank.

8. In a reinforced abrasive disk of the type carried upon a rotatablesupporting wheel, the combination comprising a reinforcing mesh, a bodyof abrasive material molded about said mesh and having a mounting facethereon, a mounting nut imbedded within said body and having anexternally threaded shank projecting through one of the interstices ofsaid mesh, a clamping nut disposed in threaded engagement with theprojecting end of said shank and in clamping abutment with the marginalportion of said mesh surrounding the interstice, a laterally enlargedhead integral with the opposite end of said shank and also disposed inclamping abutment with the surrounding marginal portion of said mesh,said enlarged head terminating in a stationary bearing surface coplanarwith the mounting face of said disk, said stationary bearing surfacebeing substantially larger than the cross-sectional area of said shank.

9. In a reinforced abrasive disk adapted for mounting upon a rotatablesupporting wheel, the combination comprising a reinforcing mesh, a bodyof abrasive material molded about said mesh and having a mounting facethereon, a mounting nut imbedded Within said body and having a shankprojecting through one of the interstices of said mesh, the projectingend of said shank being upset laterally, a spring Washer snapped overthe upset end of said shank and into clamping abutment with the marginalportion of said mesh surrounding the interstice, a laterally enlargedhead integral with the opposite end of said shank and also disposed inclamping abutment with the surrounding marginal portion of said mesh,said enlarged head terminating in a metallie stationary bearing surfacecoplanar with the mounting face of said disk, said stationary bearingsurface being substantially larger in area than the cross-sectional areaof said shank to prevent the transfer of clamping stress to saidabrasive body.

l0. A reinforced abrasive disk mountable upon a rotatable supportingwheel and comprising, in combination, a reinforcing mesh, a body ofabrasive molded about said mesh, said body having a grinding face and amounting face spaced axially from said grinding face, a plurality ofmounting nuts imbedded within said body and each having a shank portionprojecting through one of the interstices of said mesh, a dished washerf oreed into rigid attachment with the projecting end of each said shankand also into clamping engagement with one face of said mesh, alaterally enlarged head integral with the opposite end of each saidshank and disposed in clamping engagement with the opposite face of saidmesh, said enlarged head terminating in a stationary bearing faceaxially spaced from the plane of said mesh and coplanar with themounting face of said disk, said stationary bearing face beingsubstantially larger in area than the crosssectional area of said shank.

11. In a reinforced abrasive disk susceptible of 9 mounting upon arotatable supporting Wheel, the combination comprising a wirereinforcing mesh, a body of abrasive molded about said mesh, said bodyhaving a grinding face and a mounting face, a plurality of mounting nutsimbedded Within said body and each having a shank projecting through oneof the interstices of said mesh, a laterally enlarged tapered endportion integral with the projecting end of each said shank and disposedin clamping engagement with the marginal portion of said meshsurrounding the interstice, and a laterally enlarged head integral witheach said nut and also disposed in clamping engagement with saidmarginal portion of said mesh, said head having an exposed face defininga stationary bearing area coplanar with the mounting face of said disk,said stationary bearing area being larger than the cross-sectional areaof said shank.

VERNON L. LOOFBORO. ROBERT A. WHITE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,261,146 Marble Apr. 2, 19181,489,373 Tomkinson Apr. 8, 1924 1,711,453 Carr Apr. 30, 1929 1,742,052Anderson Dee. 31, 1929 1,812,076 Beebe June 30, 1931 1,964,537 Shue June26, 1934

